1. Field of the Invention
The present invention relates to an induction heating coil.
2. Description of Related Art
An induction heating coil may be used in order to, for example, subject metal machine parts such as a shaft to a heat treatment by high frequency induction heating (see JP 2013-136819A, for example). An induction heating coil disclosed in JP 2013-136819A includes a circular ring-shaped coil section which is constituted to surround a shaft serving as a treatment target. A large current is supplied to the coil section to operate it to carry out the induction heating.
This high electrical current is supplied to the coil section via, for example, a metal member (power supply section) that is brazed on the coil section. Furthermore, the coil section is cooled because its temperature increases. For preventing the temperature increased, a cooling water passage is provided in the inside of the power supply section and the inside of the coil section.
Cooling water reaches the inside of the coil section through the inside of the power supply section, and cools the coil section. The cooling water that has passed through the coil section is returned through the inside of the power supply section.